Hard disk devices have conventionally been used in information processing equipment such as computers. Hard disk devices are now mounted not only as external storage devices for computers but also in home appliances such as televisions and camcorders, and automotive electronics.
A conventional hard disk device 200 illustrated in FIG. 29 has a drive mechanism housed in a casing body 201. The drive mechanism has a spindle 203 that rotatably drives a hard disk 202 serving as a recording medium, a carriage 205 that supports a magnetic head 204 recording information and reading information on/from the hard disk 202 and pivots over a surface of the hard disk 202, a voice coil motor (VCM) 206 that allows the carriage 205 to precisely pivot to control scan with the magnetic head 204, a pivot shaft 207 that is fixed to the casing body 201 and rotatably joins the casing body 201 to the carriage 205, and a tolerance ring 208 (see FIG. 30) that fixes the carriage 205 and the pivot shaft 207 to each other. The pivot shaft 207 is, for example, approximately shaped like a column and has a structure of a bearing.
FIG. 30 is a perspective view illustrating the configuration of the tolerance ring in the conventional hard disk device. The conventional tolerance ring includes, as in this tolerance ring 208 illustrated in FIG. 30, a base 208a that is formed of a strip-like member substantially wound around in a predetermined direction into a ring shape. The tolerance ring 208 has a plurality of projections 208b (contact portions) on the outer peripheral surface of the base 208a. The projections 208b each protrude to be convex from a substantially rectangular strip-like region. After the tolerance ring 208 is inserted into an opening in the carriage 205, the pivot shaft 207 is press-fitted into the inside of the tolerance ring 208.
As such a tolerance ring, a tolerance ring having a plurality of convex contact portions protruding on the outer peripheral side is disclosed (see, for example, Patent Literatures 1 to 5). In the tolerance ring disclosed in Patent Literatures 1 to 5, the contact portions are in pressure-contact with the side surface of one of the carriage and the pivot shaft to fix the carriage and the pivot shaft to each other.
Preferably, the tolerance ring is capable of elastically deforming in the carriage and is held in position such that a shape thereof along the winding direction takes a substantially circular shape that is roughly equal to the shape of the opening on the carriage side.